First Demonstration of Oxide Semiconductor Nanowire Transistors: a Novel Digital Etch Technique, IGZO Channel, Nanowire Width Down to ~20 nm, and Ion Exceeding 1300 μA/μm

We report the first realization of oxide semiconductor based nanowire field-effect transistor (NW-FET) having ultra-scaled amorphous Indium-Gallium-Zinc-Oxide (α-IGZO) nanowire channel (width down to ~20 nm) enabled by a novel digital etch technique. A device with ~25 nm nanowire width (W
NW
) and 100 nm channel length (L
CH
) achieves the highest peak extrinsic transconductance (G
m,ext
) of 612 μS/μm at V
DS
= 2 V (456 μS/μm at V
DS
= 1 V) among all IGZO-based transistors, and the highest on-state current (I
on
) of 620 μA/μm at V
DS
= 1 V and V
GS
– V
TH
= 2 V among all oxide semiconductor based transistors with top gate structure. I
on
exceeds 1300 μA/μm at higher bias voltages. In addition, a peak intrinsic transconductance (G
m,int
) of 915 μS/μm at V
DS
= 2 V (609 μS/μm at V
DS
= 1 V) were realized.